This invention relates to optical fiber connectors and splices and, in particular, to connectors and splices in which optical fibers are held with their cores in aligned butting relationship.
In order to achieve the efficient transfer of light from the end of one optical fiber into the end of another butted against the first it is necessary to bring the fiber cores into substantial alignment. This may be effected by providing the two fiber ends with reference surfaces whose position relative to the respective fiber cores is accurately known. Alignment of the cores is then effected by bringing these reference surfaces into appropriate alignment.
This invention is concerned with the use of cylindrical reference surfaces centered on the fiber cores. The reference surface that is used may be the surface of the fiber cladding or it may be the surface of a ferrule-type termination secured to the fiber in the region of its end.
Copending application of R. J. Hodges, Ser. No. 730,606, filed Oct. 7, 1976, now U.S. Pat. No. 4,087,157, assigned to the assignee of the present application, describes a permanent or demountable butt joint between the ends of a pair of optical fibers which, in the regions of their ends to be butt jointed, are provided with cylindrical reference surfaces of equal diameter each of which is coaxial with its associated fiber core. The fibers are held butted together in alignment by a close wound helix of strip material engaged around and gripping the two reference surfaces.